Waste recyclers, or materials reducing machines are used to size reduce larger materials, such as wood debris from collection yards, land clearing or demolition-type activities. An example of one such materials reducing machine can be seen in U.S. Pat. No. 5,947,395 entitled Materials Reducing Machine. Generally, waste recycling machines consist of a large rotor that contains knives or hammer teeth spaced along the surface of the rotor. Material to be size reduced is fed into the machine. The teeth of the rotating rotor strike the incoming material, thereby chipping and shredding the debris into smaller sizes. The rotating rotor also advances the debris toward an anvil. The anvil is positioned such that the material hits the anvil, where the material is further reduced by a shearing action between the hammer teeth and the anvil. As the size reduced material passes the anvil it comes in contact with a series of screens or grates which are sized to permit only a desired size of material to pass and discharge from the machine.
The screen pattern and size of the holes can vary. For example, screens can have holes that are round, octagonal, square, etc. as well as varying diameters depending on the ultimate size of the end product desired by the user. Although the bulk of the material is reduced prior to engaging the screens, the screens can further act as a size reducer. In such a case, as the rotor advances the size reduced material past the screens the material gets further reduced by the hammer teeth grating material along the screen hole pattern, thereby shredding and further reducing the material, and forcing it out the screen holes. Often the need arises to change these screens. One reason to change the screens might be that the screen has been used long enough such that the bottom edges of the holes have dulled to the point that they are no longer effective in size reducing and screening the material. Screens may also need to be changed if the operator of the waste recycler desires a different product, which includes screening the material by a different size. In such cases the screens must be removed from the machine and replaced.
The screens are typically made of a heavy-duty material, such as steel, and are often extremely large, heavy and awkward to manipulate. To remove and replace a screen in current materials reducing machines, typically one or more individuals must completely disengage the machine and gain access to the screens through the top front portion of the machine. Access to the screens is obtained by pivoting what is known as the anvil housing upward such that the rotor is exposed and the screens surrounding the rotor can be removed. Typically, one screen, which is held into place by the anvil housing will be relatively accessible once the machine is open and the anvil housing is disengaged. The other screens, however, are more difficult to access as they must be slid up from toward the bottom of the rotor to the access opening created by the disengagement of the anvil housing, either by the operator's brut force, or by using some sort of mechanical assistance for sliding or rotating the screen up towards the access location. Further, the screens take a substantial amount of abuse during operation, which may cause the screens to deform and make removal thereof even more difficult.
Current materials reducing machines have proven to be cumbersome and extremely difficult for an operator to effectively and rapidly manipulate screens in order to change screens depending on product requirements or replace the worn out screens. As such, there exists a need for a materials reducing machine where the screens can be readily changed without significant disassembly and effort to access and remove the screens.